The present invention relates to a printing device, specifically, to an ink jet printing device. The present invention also relates to a printing process using such a device.
The object of almost all the printing technologies developed today is to produce high quality copies as fast as possible, at the lowest possible cost.
The printing process, in technologies relevant to thermal ink jet heads, conventionally has two steps. The first step consists in forming an ink drop and the second step consists in ejecting the ink drop from the ink jet head towards a receiving support. The formation of the ink drop requires raising the ink found in a channel to a high temperature in a very short time. This method requires heat in the volume of the ink jet head itself, which must then be dissipated. The drop can be ejected by different techniques, for example by the application of an electrostatic field.
One of the ink jet technologies in order to achieve fast printing consists in the use of a plurality of nozzles on the head surface that can eject ink drops in order to print a larger number of points in parallel on the receiving support. However, the number of nozzles on the head surface is restricted either because of problems related to heat dissipation in methods that consist in carrying high temperature ink as in the technologies developed by Canon and Hewlett Packard, or because of problems related to dimensional instability due to the vibrations caused by the use of piezoelectric technologies like those developed by Seiko-Epson.
Among the known methods, print devices have to be developed containing micro-elements that are generally very costly.
In ink jet technologies, the main issues are to improve the printing quality, cost and speed.
The present invention proposes the provision of a new printing device using polymers exhibiting specific properties.
The present invention relates to a printing device comprising a polymer element capable of switching from an initial state to a final state when subjected to an event, the initial state and the final state being selected from an hydrophilic state and an hydrophobic state provided that the initial state differs form the second state, and a controller adapted to generate the event producing the switch on a localized zone of the polymer element.
The present invention also relates to a method that comprises impregnating with a printing fluid a polymer element capable of switching from an initial state to a final state when subjected to an event, the initial state and the final state being selected from an hydrophilic state and an hydrophobic state provided that the initial state differs form the final state, generating an event for producing the switch of the polymer element thus forming at the polymer surface a printing fluid drop, and contacting the drop fluid with a printing receiver element.
The present invention has the advantage of forming a heat dissipating ink jet head. In fact, the ink jet head is created at the moment of use and for the duration of this use. The printing device of the invention allows printing a low temperature, avoiding any problems relating to the heat dissipation. The invention device eliminates any need for complex mechanics such as those used in known ink jet heads. The device of the present invention has a low manufacturing cost.